firmware/pwmled.c

   1 #include <avr/io.h>
   2
   3 #include "lights.h"
   4
   5 typedef struct {
   6         uint16_t target, pwm;
   7         int16_t err_sum;
   8         unsigned char mode, state;
   9         union {
  10                 unsigned char probe_steady, mode_changed;
  11         };
  12         uint16_t mode_pwm[N_PWMLED_MODES];
  13         int16_t err_sums[N_PWMLED_MODES];
  14 } pwmled_t;
  15
  16 pwmled_t pwmleds[N_PWMLEDS];
  17
  18 #define PWMLED2_TESTING_WITH_350MA_LED
  19
  20 #define SENSE_MOHM      33      /* 0.033 Ohm */
  21 /*
  22  * Voltage in uV at ADC reading == 1 is 1100/gain/1024
  23  * ADC module returns sum of 1 << PWMLED_ADC_SHIFT measurements
  24  * Voltage in uV measured is current in mA * sense resistance in mOhm
  25  */
  26 #define MA_GAIN_TO_ADC(ma, gain) ((uint16_t) \
  27         ((uint32_t)(ma) \
  28         * (SENSE_MOHM) \
  29         * (1 << (PWMLED_ADC_SHIFT)) \
  30         * 1024 \
  31         / (1100000/(gain))))
  32
  33 static uint16_t adc_max[N_PWMLEDS] = {
  34 #ifdef TESTING_FW
  35         MA_GAIN_TO_ADC( 400, 20),
  36         MA_GAIN_TO_ADC(  30, 20),
  37         MA_GAIN_TO_ADC( 800,  1)
  38 #else
  39         MA_GAIN_TO_ADC( 900, 20),
  40         MA_GAIN_TO_ADC(  30, 20),
  41         MA_GAIN_TO_ADC(2500,  1)
  42 #endif
  43 };
  44
  45 static uint16_t adc_vals[N_PWMLEDS*N_PWMLED_MODES] = {
  46 #ifdef TESTING_FW
  47         /* pwmled0 */
  48         MA_GAIN_TO_ADC(  50, 20),
  49         MA_GAIN_TO_ADC( 100, 20),
  50         MA_GAIN_TO_ADC( 350, 20),
  51         /* pwmled1 */
  52         MA_GAIN_TO_ADC(   5, 20),
  53         MA_GAIN_TO_ADC(  10, 20),
  54         MA_GAIN_TO_ADC(  20, 20),
  55         /* pwmled2 */
  56         MA_GAIN_TO_ADC(  50,  1),
  57         MA_GAIN_TO_ADC(  80,  1),
  58         MA_GAIN_TO_ADC( 150,  1)
  59 #else
  60         /* pwmled0 */
  61         MA_GAIN_TO_ADC(  50, 20),
  62         MA_GAIN_TO_ADC( 100, 20),
  63         MA_GAIN_TO_ADC( 350, 20),
  64         /* pwmled1 */
  65         MA_GAIN_TO_ADC(   5, 20),
  66         MA_GAIN_TO_ADC(  10, 20),
  67         MA_GAIN_TO_ADC(  23, 20),
  68         /* pwmled2 */
  69         MA_GAIN_TO_ADC( 150,  1),
  70         MA_GAIN_TO_ADC( 300,  1),
  71         MA_GAIN_TO_ADC(1500,  1)
  72 #endif
  73 };
  74
  75 #define ST_DISABLED 0
  76 #define ST_OFF      1
  77 #define ST_PROBING  2
  78 #define ST_ON       3
  79 // The above are constructed so that the following work:
  80 #define ST_IS_ON(s)     ((s) & 0x02)
  81 #define ST_CAN_SET_MODE(s)      ((s) & 0x01)
  82
  83 void init_pwmled()
  84 {
  85         unsigned char i, j;
  86
  87         for (i = 0; i < N_PWMLEDS; i++) {
  88                 pwmled_t *led = pwmleds + i;
  89                 led->err_sum = 0;
  90                 led->target = adc_vals[i*N_PWMLED_MODES];
  91                 led->mode = 1;
  92                 led->probe_steady = 0;
  93                 led->state = ST_PROBING;
  94                 led->pwm = 1;
  95                 pwm_set(i, led->pwm);
  96
  97                 for (j = 0; j < N_PWMLED_MODES; j++) {
  98                         led->mode_pwm[j] = 0;
  99                         led->err_sums[j] = 0;
 100                 }
 101         }
 102 }
 103
 104 void pwmled_set_mode(unsigned char n, unsigned char mode)
 105 {
 106         pwmled_t *led = pwmleds + n;
 107
 108         if (!ST_CAN_SET_MODE(led->state))
 109                 return;
 110
 111         if (led->mode) { // save the previous state
 112                 led->mode_pwm[led->mode - 1] = led->pwm;
 113                 led->err_sums[led->mode - 1] = led->err_sum;
 114         }
 115
 116         led->mode = mode;
 117
 118         if (mode > 0 && mode <= N_PWMLED_MODES) {
 119                 led->target = adc_vals[n*N_PWMLED_MODES + mode - 1];
 120                 led->state = ST_ON;
 121                 led->pwm = led->mode_pwm[mode - 1];
 122                 led->err_sum = led->err_sums[mode - 1];
 123                 led->mode_changed = 1;
 124                 pwm_set(n, led->pwm);
 125         } else {
 126                 led->state = ST_OFF;
 127                 pwm_off(n);
 128         }
 129 }
 130
 131 #define PWMLED_PROBE_STEADY_COUNT 10
 132
 133 static inline unsigned char pwmled_probed_ok(unsigned char n, uint16_t old_pwm)
 134 {
 135         pwmled_t *led = pwmleds + n;
 136
 137         if (led->pwm == old_pwm) {
 138                 if (led->probe_steady < PWMLED_PROBE_STEADY_COUNT)
 139                         led->probe_steady++;
 140         } else {
 141                 led->probe_steady = 0;
 142         }
 143
 144         if (led->probe_steady < PWMLED_PROBE_STEADY_COUNT
 145                 && old_pwm <= led->pwm)
 146                 return 0;
 147
 148         // probed OK
 149         led->mode_pwm[led->mode - 1] = led->pwm;
 150         led->err_sums[led->mode - 1] = 0;
 151
 152         // next mode to probe?
 153         if (led->mode < N_PWMLED_MODES) {
 154                 led->probe_steady = 0;
 155                 led->err_sum = 0;
 156
 157                 led->mode++;
 158                 led->target = adc_vals[n*N_PWMLED_MODES+led->mode-1];
 159
 160                 return 0;
 161         } else {
 162                 unsigned char i;
 163
 164                 led->state = ST_OFF;
 165                 pwm_off(n);
 166
 167                 log_byte(0xF0);
 168                 log_byte(n);
 169                 log_word(jiffies);
 170
 171                 for (i = 0; i < N_PWMLED_MODES; i++)
 172                         log_word(led->mode_pwm[i]);
 173
 174                 log_flush();
 175
 176                 pattern_reload();
 177
 178                 return 1;
 179         }
 180 }
 181
 182 static inline void pwmled_err(unsigned char n)
 183 {
 184         pwmleds[n].state = ST_DISABLED;
 185         pwm_off(n);
 186
 187         log_byte(0xF1);
 188         log_byte(n);
 189         log_word(jiffies);
 190         log_flush();
 191 }
 192
 193
 194 void pwmled_adc(unsigned char n, uint16_t adcval)
 195 {
 196         pwmled_t *led = pwmleds + n;
 197         uint16_t old_pwm;
 198         int32_t sum;
 199         unsigned char shift;
 200
 201         if (!ST_IS_ON(led->state))
 202                 return;
 203
 204         if (led->state == ST_ON && led->mode_changed) {
 205                 led->mode_changed--;
 206                 return;
 207         }
 208         // FIXME: test for maximum adcval value (adc_max[n])
 209
 210         old_pwm = led->pwm;
 211
 212         shift = led->state == ST_PROBING ? 3 : 8;
 213
 214         sum = ((int32_t)led->pwm << shift)
 215                 + led->err_sum + led->target - adcval;
 216
 217         if (sum < 0)
 218                 sum = 0;
 219
 220         led->pwm = sum >> shift;
 221         sum -= led->pwm << shift;
 222         led->err_sum = sum;
 223
 224         if (led->pwm >= PWM_MAX
 225                 || (n == 1 && led->pwm > PWM_MAX/2 && adcval < 0x08)) {
 226                 pwmled_err(n);
 227                 return;
 228         }
 229
 230         if (led->state == ST_PROBING)
 231                 if (pwmled_probed_ok(n, old_pwm))
 232                         return;
 233
 234         if (led->pwm == old_pwm)
 235                 return;
 236
 237         pwm_set(n, led->pwm);
 238 }
 239